There is a growing tendency to package many articles in plastic film type enclosures rather than in cardboard cartons or the like, particularly when there is a shortage of paper products. For example, many canned and bottled food products are now being packaged by placing them on simple cardboard or plastic trays and then passing them through conventional heat shrink apparatus in which they are wrapped in a shrinkable film material, usually polyethylene, which is then heat shrunk in place. This packaging technique is used in cases in which it has been conventional in the past to use cardboard cartons. These individual packages, which may consist of twelve or twenty-four cans or bottles of a product, are then loaded on pallets for shipment. Because they slide relatively easily with respect to one another they must be anchored to the pallet by some suitable means. It is common to do this using shrink wrap palletizing techniques, wherein the pallet and load is enclosed at least in part by a sheet or sleeve or pre-formed enclosure formed of heat shrinkable film and then passed through a shrink tunnel where heat is applied and the film tightly shrunk about the load. One of the most commonly used heat shrink materials for this purpose of polyethylene film, however it has been discovered that when such film is shrunk on loads of individual packages where the packages themselves are wrapped in polyethylene film, the shrinking heat applied in the tunnel causes the outer polyethylene sleeve or bag to fuse to the individual packages on the pallet, thus making it difficult if not impossible to remove the individual packages intact from the pallet when they reach their destination.
It is therefore a primary object of the present invention to provide a packaging system, including method, film and package, which permits utilization of relatively inexpensive and readily available polyethylene as the primary shrink wrap material and which obviates the aforementioned disadvantage of known techniques. A related object resides in the provision of an improved shrink wrap material having greater toughness and strength than the commonly used polyethylene film.
These and other objects of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.